The Search option is your friend.
Now with that said, I would suggest looking through Egan's write up on his lift.
http://www.elcovaforums.com/forums/s...highlight=inch
From what I know, you can put 37s on your stock rig with little to no clearance issues. Just depends on various things like the width or the wheel offset. Of course to play it say Egan did a 2 inch "mini lift" and when done was able to fit 37s without issue. I think I asked him the cost and I think he told me about 500, but that he already did the rear spring conversion too so that amount wasnt added into the 500.
The best thing to do, IMHO, would be to get with Egan.
Unless he chimes in on this thread.
As for a street queen, ummm well I would say a decent street tire. Given it is hard for me to say because I want a good street tire but I also want something there in case I do take her into the dirt. Personally I get a good all terrain, ie BFG K/Os but then again if you just want street.... well then you could get into something else that would last longer.
As for offset... well thats up to you and what you want. It is also up to you in regards to the amount of steering hassle you have. I mean you havent told us if you want them to stick out, be even with the fenders, look like stock..... etc etc
Anyways I hope this helps